Technical Report for the Fort Knox Mine - Kinross Gold

Fort Knox Mine Technical Report9.0 MINERALIZATIONThe Fairbanks mining district is a celebrated placer gold camp with production in excessof 8.0 million ounces of gold since 1902. Although a significant mining district in terms oftotal production, it had only limited lode production until the discovery and developmentof the Fort Knox deposit in the late 1990’s. The discovery and development of the TrueNorth deposit (Figure 4-1) produced ore for the Fort Knox mill from 2001 to 2004, andfurther enhanced the lode production from the district.Although the regional distribution of gold mineralization in the Fairbanks district isbeyond the scope of this report, the area hosts gold in a variety of geologic settings, asfollows:• The Fort Knox deposit (the largest lode deposit in the district) is characterized bymineralization in quartz, quartz-sericite and quartz pegmatite veins, stock workzones, and mineralized shear zones;• True North mineralization is hosted by complexly deformed, carbonaceous metasedimentsassociated with quartz veins;• The Ryan Lode deposit, gold occurs in and adjacent to large-scale shear zones;• The Gil project, gold is hosted in skarns and quartz veins within the skarns;• The Cleary Hill mine, gold occurs in quartz veins within the Fairbanks Schist.9.1 Fort Knox DepositThe Fort Knox deposit is hosted entirely within the Fort Knox Pluton. The pluton iselongate and measures approximately 1100m east-west and 600m north-south. Drillinghas identified mineralization to the 400 level which marks the lowest extent of detailedinformation. The contact with the Fairbanks schist is abrupt, and drilling indicates thepluton contacts plunge steeply to the east and moderately to the north, south, and west.The Fort Knox pluton has been subdivided into three mappable phases based ontextural differences. Intrusion of the biotite-rich fine-grained granite was followed by amedium-grained porphyritic granite. The youngest intrusive phase is a coarse-grained,28